Scratchbuilding models is an ever continuous learning curve. With each model you can face new difficulties or experience new challenges but as time goes on you build up a mental log of tricks and tips that help you overcome the difficulties and enhance the challenges. When it comes to kit cars, you can need as much guile and skill as required for a true scratchbuilt model. Surely, all the parts come in the box and some kits all you need is a spanner and a screwdriver. But there are some kits which entice you with their subject matter and lead you on, only to pit you into frustration once the kit has been opened.

The Ostorero kits could be that challenge and my advice would be to try them but approach them cautiously. They consist of some simple engineering which requires a modicum of common sense but they also contain a build element which, in order to make them look good when completed, must be approached sensibly and a lot of forward thinking.

The model in question was gratefully passed on to me for assembly by fellow local slot racer (and budding scratch builder) Paul Stevens. Paul is quite able to complete the task in hand and has already finished one very nicely to his credit. This model he kindly asked me if I would like to assemble and do a blow by blow on the forum. Who could resist such a challenge!! So with kit under arm I returned from an evenings racing at Red Racer Hobbies looking forward to the experience.

It was several days before I could start it as I was restoring a couple of models for other racers plus I had a race management hardware problem to solve for another, but this weekend saw a bit of clear air and I have made the first tentative steps in construction.

First up was an inspection of the parts and the instructions. I use the term instructions loosely as it is more a series of photographs of the model in various states of assembly with a sequence of numbers which may or may not be the assembly order in code. Common sense tells me to check out the kit thoroughly and look at the guide sheets and plan the attack

The kit comes in a plain, clearly marked box and once opened a degree of care has been taken to protect the model from transit damage. Unfortunately, the first and only casualty was a broken roll cage over the driver. The body parts of the kit are almost exclusively resin with one or two etched parts. The roll cage was attached to the body, possible for colour matching but has been snapped off at the base. This won’t present too much problem later on as I will fabricate one from music wire which may well be a plus.

Parts are kept apart in their sealed bags and an inventory check shows all to be there, next comes the plan of attack. First temptation is to assemble the chassis and get it running a.s.a.p. but that would leave gaps in construction, how come? The resin parts will need to be carefully removed from their sprues and seriously fettled to get them into a presentably usable state. The mouldings are quite accurate and the resin compound has a fibrous content which gives the parts better strength than straight resin. This is a godsend as some of the parts are that fine that it was going to be hard to keep everything intact.

I started by trimming all the resin parts from their sprues and fettling the flash from them. The main tool for this was the side of a modellers knife and back up was some modelling files and some 600 wet and dry. The wheel trims and steering wheel were painstakingly trimmed and long parts like the exhaust and the steering drag ling were cleaned. Some extra fine detail on the rear suspension parts and the driver too needed attention before I could start applying the first coats of paint.

Handling these tiny parts too can be a problem if you are blessed with a bunch of numb saveloys on each hand as I am. So, to minimise getting paint from stem to stern on everything, I have devised some simple parts holding devices whilst I’m painting. Firstly is the sticky stick! This is a small piece of MDF with masking tape wrapped around one end in reverse. (I got the idea from a lint brush for cleaning fluff from suits and things).

Most small parts will sit on the fresh sticky side of the tape and indeed can be inverted and all sorts. This helps to get into the nooks and crannies of the smallest parts. It is not essential to paint the entire piece in one go so, one you have covered the bulk, after the paint has cured you can move the part on the stick. I have found this invaluable on several occasions.

The sticks can also carry a multitude of holes and cut-outs to fix things for painting, like square or round holes for drivers heads, steering wheels etc.....

The other aid is a small crocodile clip. This can be used to grip parts for painting and if used correctly, the wet parts can be stood out of harms way to dry, leaving vices and the like for other duties. Using plastic enamel paint, I then progress on to painting the first coat onto the parts. First coat? I hear you say,

Yes you did. I don’t believe in a thick, one coat paint job for these parts. Invariably the paint is a bit thick and can be lumpy and attracts dust and bubbles in the finish. I thin the enamel to quite watery consistency (not too watery) and paint each part. It looks a bit thin and you will see the original material underneath but after drying and the application of the second coat you will see what I am getting at. The coating, if you have prepped the resin properly, will be smooth and blemish free, and solid.

Another thing I am fond of doing, which came about after being given some old Scalextric spectators to repaint, is to mix paint for different jobs. This isn’t essential, but sometimes you can be caught without a colour and a trip to the hobby store at 9.00pm isn’t normally viable. I have painted the steering wheel with its first coats. There is a repair to be done on the boss but I have painted the rim with its first coat of brown (supposed to emulate a wooden rim) and silver (alloy) spokes.

The brown was mixed using red, yellow and black and I use a small off-cut of 3.0mm MDF as a palette. The other good thing about two coating parts is that you may not be happy with a colour you have applied and the second coat can be lightened or darkened or tinted according to what you want to do and, providing it isn’t too much of a departure from the original, it will cover in the one extra coat as before.

After all this activity there is a mandatory drying time for the parts. A couple of hours at least, no sooner! None of this “race ‘em while they’re wet” business!! So this is an opportunity to move on to the business end of the parts. The wheels were unpacked and admired. Very sturdy alloy rims in which the inserts will sit. I’m most impressed by the tyres too.

This model has a Slot.it type motor so it will be travelling at a good rate of knots. It has a fair traction magnet but the tyres still need to be on the ball and these are. A good soft compound with excellent print to the sidewalls, right down to the direction of rotation arrows!!

First job on the chassis proper is to pop up all the tags that will be holding the essentials, axle and motor mounts. The chassis looks to be etched too and the paleness of the brass tells me it could be softer than expected. This would be to aid bending of the tabs. Too hard a metal would see this thin metal fracture internally or with use. I do this with some square ended pliers. Firmly gripping the tab just behind the line, I bend it cleanly and in one action to as near 90 degrees as possible.

The angle can be checked with the butt end of a small steel rule. Be careful not to bend the tab backwards and forwards trying to achieve 90 as this also can induce stress fractures inside the metal. A couple of adjustments at the most should be enough!! CAUTION. DO NOT BEND the tab in the wrong direction, attempting to rectify this may well see it snap off altogether!!

Next up will be the tab which carries the prop shaft at the rear. Remember, this is a front engined model. Once the tab has been levered up enough with the blade of a modellers knife, grip it with the pliers and move it in one go to its correct position, bending only again for fine adjustment.

This is the opportunity to fit the chassis out but this isn’t as straight forward as might be expected so caution is the bye word when proceeding. The thing to keep mostly in mind is not to exert too much pressure on the chassis. It’s quite thin really and in a moment of aligning parts you could be at real risk of putting a curve in it which will be a disaster for parts alignment, so, off we go!

First up the motor needs to go into the rear mount, simple enough! Next, the front mount. A right angled bracket with the tiniest of screws. It is my view that the screw thread is too small for a conventional slotcar mount but I doubt this model will be sustaining full on racing impact. But, If you do intend to race this model in the cut and thrust I suggest you source a meatier screw or solder the bracket in place!.

Next up it is best to fit the propshaft and axle bearings. I thought at first of gluing them in but there isn’t enough material around them to ensure an effective bond so I decided to sweat them in. The mating surfaces where sanded with a piece of 600 wet and dry and one by one the bearings were fitted in place. I have two soldering irons to hand, A twenty five watt for small wiring and circuit work and a forty watt for this type of soldering. The hot tip was placed against each bearing in place and one by one, some five core solder was dabbed on each side of the bearing at its join with the chassis. Just enough to hold the bearing safely in place.

The propshaft needed the pinion fitting, this was done in a small vice and it was pressed on until, offering up the crownwheel, there was enough poking through to sit comfortably in the crownwheel slot. The transmission spring was twisted onto the motor shaft and next the prop shaft complete was fitted. Note here that it is detrimental to lever these springs on and off with pliers and the like and totally unnecessary! Simply grip the shaft lightly and with finger and thumb, twist the spring in the direction of the coil end and the spring coils will give enough to allow the spring to slide on smoothly. The same goes for removing the spring, twist it in a forward direction and pull off at the same time. Note here that if you have soldered the bearing in crooked or not bent the bearing bracket enough, the shaft and motor will feel tight because they are binding in the misaligned hole!

Next up is the guide and front axle. At this stage I have desoldered the lead wires from the motor for obvious reasons which I will mention later. The guide looks to be a Slot.it type and it comes with a novel fixing device. Firstly, there is a nylon collar sitting on the pin. Poke the guide through its hole and fit the second nylon washer over it. Next, there is a short spring in the kit. Slide this over the guide pin until it exerts minimal pressure on the washer. This will hold the guide comfortably in position and will minimise side and end play.

I’m still not sure that the front axle is correctly mounted but I studied the illustration until I was totally confused? But I think it could be right now. The long compression spring is supposed to sit over the front axle snugly and hold it in place! The only trouble is that it isn’t snug and it won’t hold it in place. The only solution to be had was to bend the spring in the middle.

This then allowed the axle to pass through it but still exert a good force on the axle to minimise the possibility of it moving. If that IS the correct mounting then I would either be inclined to solder the spring in place or discard it and fit a couple of aeromodeller grubscrewed collars either side as I do with my ‘Wixle’ set up! Anyhow, the axle is fitted and is fairly rigid. The front axle too is sloppy in its holes; this will no doubt translate into noise on the track

Now back to the lead wires. I hate models were lead wires pass round the inside of a model several times before connecting guide to motor, check out the Spirit BMW 2002 review, I had enough wire left over to do two more models. In this case I desoldered the wires from the motor, fitted the sleeves to the other end and pushed the sleeves into the guide holes with the little tail of lead wire making firm contact with the braid material. This creates more of a snug fit and minimises the risk of the sleeves working their way back out over time. I then positioned the lead wires round the motor and trimmed them to just past the motor brush contacts. The bared ends were tinned and with a quick manoeuvre dabbed the two together with a hot soldering iron.

The rear axle was tested in the bearings and once happy, I slid it in with the gear in place. The axle was centred and the grub screw in the crown tightened. Almost the last chassis job is to fit the wheels. The instructions say to glue these on?? Hopefully a misinterpretation? Anyhow, as there are grub screws in them I used those instead! Lastly, the motor and bearings were lubed and the contrate got a good serving of Vaseline. This has an alloy hub and I’ve already fallen foul of one dry alloy gear hub in the past! The wheels had already had their painted inserts fitted. These were superglued in place and the spinners tried for an easy fit, then also superglued to the wheel trims.

At this stage it would be prudent to ensure the chassis fits in the body. There is going to be a lot of body handling as it is and the last thing we want is to start damaging decals while we fit other parts. In this case, most of the resin parts were offered up to see if they were going to fit. All was ok and the next fit was the chassis. It’s a bit fiddly to get the lead wires down alongside the motor and past the front screw holes but it will need to be done.

On this model the front screws were fine but on the rear the screw holes were drastically out of align, what to do? One thing’s for sure, with these tiny screws there’ll be no pre stressing the chassis or trying to get the body to give, uh! uh! This will be a recipe for disaster down the line sooner or later.

The only solution is to cut the chassis through at the holes and install the screws with a couple of fine washers on them. We don’t want to be taking screws in and out if we can help it. The only other thing was to cut out room for the washers in the body. This was achieved with a grinding bit in the ‘dremel’ tool. Once the chassis was ok’d it was time to move on

It’s now time to move back to decorating the mode, but first up there is the small matter of painting the dash area either flat or satin black. This will be taking a white decal and it will stand out much better on a black background. Having already given the decals a thin coat of clear lacquer I trimmed the larger red flashes out of the sheet. These decals are amongst the largest for the model and they will need to match each other in place so I decided to get these out of the way first. One pair go to the front and the other to the rear.

As well as matching up they need to align with some of the body features and they will also act as a guide when fitting some of the smaller decals. Both fronts were trimmed to size and using tweezers, dipped in cool water for five seconds. After about thirty seconds the decal will loosen on its backing paper.

The area to be covered was swabbed lightly with the damp end of a cotton bud, this minimises the risk of a decal ‘freezing’ before you get it in place. Moving the decal slightly on the backing you can grip the backing paper with the tweezers and after placing the loose end of the decal near its resting place and holding it there with the damp end of the cotton bud, carefully pull the backing paper to one side until the paper is fully removed and the decal is on the body hopefully near its final resting place.

Any adjustment can be made by sliding the decal into place with the damp end of the cotton bud. When you are happy with its position, touch the edge of the decal with the dry end of the cotton bud. This will suck the moisture from under the decal and it will sit flat on the body. Once happy with its position it is a careful but simple task to then roll the decal carefully from the centre out with the dry end of the cotton bud. This will squeeze out most of the remaining moisture and the decal will be fixed at this position. The larger decals overlap just a little and once dried out the join will be almost imperceptible.

An interesting note here. If you put a decal in the wrong position or out of align it is possible to ‘re hydrate’ it. Using the wet end of the cotton bud, swab the decal (don’t rub it!) and leave for a few minutes and the decal should float on the water. If it hasn’t worked, swab it again and leave it for a while longer.

Once you are happy with the decals it is usually best to leave them for a few days to harden off. They will still be sensitive to touching for a little while so get on with another model or read a book!

The time is approaching fast when the model will be completed. The harder jobs will need to be tackled first as, once again; these could lead to more delicate parts being damaged by excess handling. I chose to fit out the cockpit first. The seat was epoxied in place and left to set. The screen is a vacuum formed part and this needs to be trimmed to its mould lines. The secret with these, to avoid over cutting, is to trim with a small pair of scissors leaving the smallest of lips around the screen. This can later be trimmed with a modellers file once cut out. The screen fit in the cockpit then needs to be confirmed and any other trimming carried out.

The screen on this model was scored lightly along the outside bottom edge to give it a key. I brushed a thin layer of epoxy ‘clear’ on this and on the inner edge of the cockpit and the screen was put into place with a pair of tweezers. As expected, the profile of the screen is a good, but not a great fit and there is no where to put clips to hold it in place. This can be countered by using clear epoxy. Clear epoxy takes ten minutes or so to stiffen and during this period, about every three or four minutes, you can push the screen into a snug fit with the point of a modeller’s knife. After a while it will stay in place.

The next problem to be encountered is the driver! As mentioned before he is an exact replica of the Fly open faced helmet driver and I suspect he has had a bit of trimming to fit. Even though he came in two parts, he still isn’t that good a fit, probably because I decided to assemble and paint him before installation. My first attempt saw him sitting in his seat with his right arm akimbo at the top of the screen!!?? What to do. The trouble is his bum isn’t a good fit in the seat and he needs to sit bolt upright to get his arm anywhere near the wheel! Without further ado I broke his legs at the hip, no choice. They were reglued with superglue and will be as good as ever after a repaint. Eventually the driver and wheel were placed in the model. The driver was placed on a cushion of epoxy and once in position I applied a couple of beads of epoxy to the underside of the driver in his seat and the steering shaft.

Once this was glued it was full steam ahead for the rest of the bits. The etched stainless parts were fitted and the many resin parts were glued in place. Most parts were glued from inside the model. This removed the possibility of getting glue all over the body. In the case of the exhaust and rear nurf bar the body holes were applied with epoxy using a small diameter piece of music wire. The holes were filled with resin and the part pins carefully pushed into the holes. Once again, all was left to set.

Another job which was attended to while all the drying was going on was the manufacture and painting of a replacement roll bar. As mentioned before, the original was broken from the box. The replacement was a simple task. I selected music wire to the nearest diameter and clamped one end in the modelling vice, against the handle of a modeller’s knife.

The wire was then slowly bent around the handle and using the broken part, was bent to a matching curve. The curve was then cut from the wire and the ends bent using two small sets of modeller’s pliers until, once again, they matched the broken parts fixing holes. The hardest bit was the colour match. The only gold I had was the same as the drivers helmet, a bit too gaudy by comparison with the body. I eventually managed to get a close match by mixing silver with gold and adding a touch of yellow gloss. Not a perfect match but not too far out!

So, just about finished. The last job was ‘snagging’. This is the process of looking around the paintwork and touching in any marked or lost paint spots. Some silver bits were touched in on the glue spots and the driver had a tickle up too. A last coat of clear on the touch up parts and that is just about that! Pheeeeeew!!! And a huge sigh of relief! It is always tempting to speed up towards the end of a model and this can be disastrous. That’s why my model bench always has six or seven projects on it, I can walk away from drying decals, or paint, or glue!

So what do you get for your money? Well, firstly and most importantly, you are getting a unique (to Ostorero) model. I am not aware of anyone else making the Watson Special commercially. Next you are getting a model which will race well if you put it to the test. Super soft tyres and alloy wheels, not to mention a ‘Slot.it’ type motor and guide blade. But the reality is that apart from a few hot laps pre race meeting or at home, this model may well take centre stage on one of your shelves amongst the other models. It has been an experience to construct and in its construction there would be several things I might change purely to make it more track friendly.

Firstly, I would have made all the ‘add on’ resin parts from pewter or similar. Another low cost casting method which would enhance the models durability. I would also give the model a final clear coat over the decals to aid longevity and I would change the final drive ratio to overcome the effect of such large rear wheels. Oh, and I would do something about the small screws that Ostorero seem fond of! Not practical! And lastly I would fix the front axle setup. That’s about it! Not too much I hope. Just a track test to follow!! A gorgeous model which, in the flesh, appeals to me greatly (from someone who has been passé about oval track cars for many years!) So what are the best prices for the Lotus 38?? Mmmmmmm!

16 03 2008 Update

I had the opportunity to take the model for a spin on my favourite surface a day or so back and this model didn't disappoint. Even with the large rear wheels it was smart off the line and the super soft tyre compound gave it heaps of traction on board. The model looked a picture doing circuits of the track and it's straight line speed wasn't shabby! You couldn't class this model as a competitor as there is little else about in it's class to compete with and I suspect that once pushed hard in a dice it would show greater tendency for bad behaviour like wheel lifting and rolling, but none the less, for doing lap after not so dusty lap in the privacy of your own race room, this model is a pleaser!

Many thanks to racer friend Paul Stevens for the unique opportunity to assemble this model. Maybe another one might be closer to my model bench than I suspect?